Sunahori Fumie X, Wei Jie, Clouthier Dennis J
Department of Chemistry, University of Kentucky, Lexington, Kentucky 40506-0055, USA.
J Chem Phys. 2008 Jun 28;128(24):244311. doi: 10.1063/1.2939011.
Subsequent to our spectroscopic detection of the C(2)X(X=P,As) free radicals [F. X. Sunahori et al., J. Am. Chem. Soc. 129, 9600 (2007)], we have studied the electronic spectrum of the (2)Delta(i)-X (2)Pi(r) system of the jet-cooled C(2)P free radical in the 490-630 nm region. The high-resolution laser-induced fluorescence spectrum of the two spin components of the 0(0) (0) band of (12)C(2)P has been recorded, and the rotational and spin-orbit coupling constants have been determined for both electronic states. The Renner-Teller effect has been observed in both the (2)Pi and the (2)Delta states, and the vibrational structure has been assigned. For the ground state, all of the observed levels up to 3500 cm(-1) were fitted with a standard Renner-Teller model. The excited (2)Delta state vibrational levels were successfully fitted using literature energy level expressions derived from perturbation theory, yielding vibrational and Renner-Teller parameters for both (12)C(2)P and (13)C(2)P. The molecular structure of C(2)P in the ground and excited states has also been estimated and compared to ab initio calculations and the geometries of similar molecules.
在我们通过光谱法检测到C(2)X（X = P，As）自由基之后[F. X. Sunahori等人，《美国化学会志》129, 9600 (2007)]，我们研究了喷射冷却的C(2)P自由基在490 - 630 nm区域内的(2)Δ(i)-X (2)Π(r)体系的电子光谱。记录了(12)C(2)P的0(0) (0)带两个自旋分量的高分辨率激光诱导荧光光谱，并确定了两个电子态的转动和自旋 - 轨道耦合常数。在(2)Π和(2)Δ态中均观察到了Renner - Teller效应，并对振动结构进行了归属。对于基态，所有观测到的高达3500 cm(-1)的能级都用标准的Renner - Teller模型进行了拟合。利用从微扰理论推导的文献能级表达式成功拟合了激发态(2)Δ态的振动能级，得到了(12)C(2)P和(13)C(2)P的振动和Renner - Teller参数。还估算了基态和激发态下C(2)P的分子结构，并与从头算计算结果以及类似分子的几何结构进行了比较。
